1. Field of the Invention
The present invention relates to an improvement of an electric extension wire, and more particularly to a flat cable type extension wire including a flat cable connected between an electric plug and a socket.
2. Description of the Prior Art
An extension wire can be conveniently used without limitation of application environment. In addition, the extension wire can be easily stored without occupying much room. So, various extension wires are commercially available for use in family, factory, store, outdoor working site, etc. Especially, a winding type extension wire can be wound up for easy storage and thus is more widely used.
A conventional extension wire includes a socket and a plug connected to the ends of a pair of electric wires. In use, the plug is plugged into an electric socket and the socket is pulled to an application position for a distal electric appliance to plug in. Such structure is quite simple and widely used in a family or a commercial store.
However, such extension wire may have two or three electric wires, depending on the power system of the application environment. Also, according to the required electric current, the extension wires with different wire diameters are selectively used. In the case of a high current load, the extension wire will have relatively large diameter electric wires. In use of such large diameter extension wire, the extension wire cannot be laid flat on the ground and thus cause a person to stumble. Moreover, it is difficult to collect the extension wire.
A conventional winding type extension wire typically includes a cable, a winding reel for winding the cable and a housing for enclosing the wound cable.
The winding reel is connected with a winding spring for providing a winding force for the cable. One end of the cable is connected with a plug, while the other end thereof is connected with a socket disposed on the housing.
However, often the extension wire in the conventional winding type is tangled during winding. For example, when winding the extension wire, in order to smoothly and evenly wind the cable into the housing, a user must very carefully adjust the winding position of the cable (for example, from left side to right side or from right side to left side).
Otherwise, the uneven left and right sides of the wound cable will lead to unsmooth winding and uneven winding force, thus resulting overlapping and tangling of the cable or even make the cable touch the inner wall of the housing and disable the winding reel from winding the cable.